Polyglyceryl ether derivatives are compounds useful for a solvent, an emulsifier, a dispersant, a detergent, a foam-boosting agent, and the like. For producing polyglyceryl ether derivatives, there is a known method of reacting an alcohol with glycidol. Such a method has been conventionally conducted by treating an alcohol with an alkali in general and adding glycidol dropwise thereto to react. There are also known methods, including a method of conducting addition polymerization of an aliphatic alcohol with a glycidyl ester and subjecting the resultant polymer to saponification with an alkali to remove an acyl group (see, JP-A 9-188755), a method of repeating a cycle of reactions to achieve an intended polymerization degree, that cycle includes reacting an alkyl glycidyl ether with glycerol to produce an alkyl diglyceryl ether, condensing a hydroxy group of the ether with an allyl halide, and converting an allyl group to two hydroxy groups (see, JP-A 2001-114720), and a method of conducting addition polymerization of an aliphatic alcohol with glycidol in the presence of a catalyst (see, GLYCIDOL: properties, reactions, applications Kleemann, Axel Dr. Alfred Huthig Verlag Heidelberg 1981).
JP-A 2001-49290 discloses a detergent composition containing a monoalkyl ether of glycerol or polyglycerol prepared from glycerol.